[Towertalk] Moving To New QTH

Chuck Counselman ccc@space.mit.edu
Fri, 18 Oct 2002 08:58:36 -0400


At 7:59 PM -0500 10/17/02, N4OX@webtv.net wrote:
>Has anyone on the list lived near, very near a 100,000 watt FM broadcast
>station tower?...  I would like to talk to anyone who has had a ham 
>station located "close" to a tower like this to find out if there 
>were any RF problems.

Interesting question, and I look forward to reading the other 
responses.  I expect that the answer depends strongly on whether your 
hamming is on HF or on VHF.  I live about 1 km away from the site of 
an FM broadcast station (power unknown) and a 5-kW, three-tower, AM 
broadcast station.  Another, 50-kW, AM station is about 3 km away. 
(I just queried the FCC database and found the AM station's license 
data but not the FM station's data.  I wonder whether the FM 
operation is defunct.)  IIRC, a calibrated broadband field-strength 
measurement in my driveway showed 0.25 volts per meter.  When I first 
moved here, you could hear both AM stations on all of the telephones, 
and the 80-m ham band was full of strong intermod products involving 
not only these two but many other AM stations.  A couple of years 
and >$1k worth of ferrite and brute-force LC filters later, all was 
quiet; but it was a lot of work tracking down and then fixing all the 
non-ohmic (i.e., nonlinear I-vs.V) connections in the house.  I will 
say that it was interesting and educational.  You would not believe 
how many unintended RF mixers are in an ordinary house.

I am strictly an HF operator, and I have never detected the slightest 
problem from the FM transmitter.  I have no idea what an FM receiver 
here would hear.

73 de Chuck, W1HIS